converter voltmeter to frequency meter

Posted on Feb 6, 2014

This is design circuit for converter meter voltage to frequency. Normally we often encountered the frequency meter can be used in speed sensor, tachometer, measurement or signal recurring. This frequency to voltage converter (FVC) can be used to change the voltage into a digital or analog tachometer. Circuit that is consists of three blocks. The f

irst block is squarer, the input signal to a square wave. This block was protected the circuit from high input voltage up to 400V, but remember this only works if the value of capacitor C1 is for 400V. Input Impedance around 560k, so it is safe to connect the ignition pick-up coil in parallel with the CDI (capacitor discharge ignition) circuits without a problem. Supply is protected from voltage spike by Zener diode D3. This is the figure of the circuit; The second block is retriggerable mono stable multi vibrator. Mono stable multi-vibrator is to convert fixed width pulses to provide output, the voltage output of the average will depend on the duty factor pulses input / waveform, but only depends on the input frequency. Pulse width is determined by R9 + R5 and C4. According to the datasheet of IC 4528, the period of the mono stable : R and C are in ohm and Farad, VDD-VSS is in the pin 16 voltage minus the voltage on pin 8, and t in seconds. Minimal value of R9, the mono stable multi-vibrator output pulse width will be 0. 2 * 4700 * 22e-9 * ln (12) = 5. 139e-5, and this will change the frequency of 19. 460 kHz to 12 Volt output. This gives a conversion factor 1. 622kHz/Volt. If you set the maximum value to R9 (100k) then the pulse width of mono stable multi-vibrator output will 1. 145 MS. This setting will give the maximum voltage output of 12V at 874Hz, or about 72. 8Hz per Volt conversion. If you use the tachometer to the...

Leave Comment

characters left:

• New Circuits

.

Popular Circuits

Battery-capacity-tester
Audio Tube Preamplifier Circuit 6DJ8 / ECC88 SRPP
Long-Range IR Transmitter
Karplus Strong Opamp Circuit
Heart-rate And Ekg Monitor Using The Msp430fg439